Kyle Atwood is a published horror author who plays too many video games and watches too many horror movies to be of sound mind.
This analysis contains major spoilers for Red Dead Redemption 2 stop now if you do not wish to be spoiled.
Arthur Morgan was born in 1863 to his parents Beatrice and Lyle Morgan. His father, a foreshadow of what his son was to become, was arrested for larceny in 1874, when Arthur was only 11 years old. Arthur held resentment for his father even as an adult even after he's committed numerous robberies and murdered a number of individuals.
Around 1878, Arthur was picked up by Dutch van der Linde and Hosea Matthews. It wasn't long until Arthur began viewing Dutch and Hosea as his adoptive father figures, and, as a result, Arthur began to share Dutch's vision of a life lived free from civilization and law, becoming one of the first members of Dutch's gang. At some time during his youth, Arthur met a girl named Mary Gilis and the two fell in love. Arthur's preference for a life of crime, however, along with Mary's family's strong disapproval of him, their relationship fell apart. After this, it is later revealed that Arthur met a young waitress named Eliza and slept with her, resulting in her pregnancy with their son Isaac. Eliza, unlike Mary, accepted Arthur's lifestyle as it had supported her and their son, even if Arthur did visit only a few days every other month. One day, on his way home to visit them, he arrived at his house and saw two crosses outside and Arthur knew immediately that they were both dead, and learned later on that they were killed by robbers. The tragedy wound up hardening Arthur as he never really coped with the pain.
Jump forward and we find that Dutch and the gang are forced to flee a city called Blackwater after a botched ferry heist. What follows is a number of botched heists and hardships as the gang just can't seem to settle down anywhere. Arthur begins to feel angry and scared for the fate of the gang as they face the ever-changing world that, he feels, has no need for them anymore.
Arthur Morgan is one of Dutch's most prominent gang members.
First and foremost, he is a physically imposing individual with natural strength and durability rivaled only by fellow gang member Charles. He is also quite skilled in a large variety of firearms, from antiques like the Volcanic Pistol, to the fully automatic mini-gun, to the Rolling Block rifle, to modern weapons like the Mauser Pistol and even a bow and arrow, despite stating he never got the hang of it. Arthur also has strong leadership skills as seen when he repeatedly leads his fellow gang members in robbing and defeating large, overwhelming amounts of men. This is not only from their respect for him but also from his abilities.
Outside of combat, Arthur's skills go above and beyond. He is a skilled interrogator, one part due to his strength, another part due to his sheer intimidating presence, and another part of the amount of practice he has had. He is also capable of producing some charm due to his outstanding charisma.
Arthur Morgan is also a very intelligent individual. While not in the 'book-smart' sense, he shows a knowledge of working machinery and transportation, such as steam engine trains. He also demonstrates a natural talent for writing and art as displayed by his numerous, detailed journal entries players can unlock. He consistently displays an aptitude for strategy and an accurate assumption for how things will play out. He is also a good judge of character.
Early on in Red Dead Redemption 2, Arthur Morgan is a seemingly cold and ruthless outlaw who, more often than not, resorts to killing and has very little qualms about doing so. However, despite being a violent individual, Arthur is playful, especially with people he cares about. He is also kind and polite as seen with John Marston's son, Jack, having a rather gentle attitude around the boy. He is also willing to help a number of members of the gang unless he finds them too wild or genuinely evil, such as Micah Bell.
Regarding his religious views, Arthur is most likely not religious, but he does believe in an afterlife and some form of a higher power.
With Arthur's ability to commit violent acts, he also has his own moral code, more notably his stance against unnecessary killing. Arthur also doesn't believe in revenge, as Dutch had raised him to believe that revenge will is nothing but a destructive path. Arthur seems to believe that violence should be cold and strictly business, never to gain satisfaction from and especially without reason.
Arthur is also extremely progressive in his views concerning women and minorities. He is disgusted by racism and has no complaints with the women in camp doing work associated with men or even having women gaining the right to vote.
Arthur understands that what he is doing is morally wrong, but justifies his behavior as being different. This is because of the beliefs behind the Van der Linde gang, that they genuinely feel they could help people. As time continued, however, Arthur realized that this philosophy was an excuse to justify Dutch's illegal activities.
Once Arthur realizes what Dutch's true intentions are, his loyalty begins to deteriorate and essentially made him endure an existential crisis, of sorts. At this point, because Dutch had raised Arthur, this philosophy was Arthur's primary belief. As the gang falls apart, Arthur realized that the way of the world is far more than what he could comprehend.
After Arthur is diagnosed with tuberculosis, and his faith in the gang is all but gone, Arthur becomes more wise and self-conscious of his own feelings. He also becomes more caring about other people more than himself. After all of the robbing and killing he's done in the name of a better world, Arthur's last objectives of life were to protect John Marston's family and ensure that they hopefully build a better life for themselves, sort of justifying the suffering of the gang in some way.
Arthur Morgan is the pinnacle of the Western outlaw archetype. Righteous in his ways but ruthless in his execution. A man just trying to survive a savage world. A character of tragedy and, most importantly, humanity. Arthur is perhaps one of the deepest characters I've had the pleasure of analyzing at this point and I had a crazy ride sharing his adventure.
I tip my hat to you Rockstar, you've certainly outdone yourselves with the character of Arthur Morgan.